package com.atguigu.day11;

import com.atguigu.bean.WaterSensor;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.tuple.Tuple1;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
import org.apache.flink.table.functions.AggregateFunction;
import org.apache.flink.table.functions.TableFunction;

import static org.apache.flink.table.api.Expressions.$;
import static org.apache.flink.table.api.Expressions.call;

public class Flink05_UDF_AggFun {
    public static void main(String[] args) {
        //1.获取流的执行环境
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        env.setParallelism(1);

        //2.从端口读取数据并转为WaterSensor
        SingleOutputStreamOperator<WaterSensor> waterSensrStream = env.socketTextStream("localhost", 9999)
                .map(new MapFunction<String, WaterSensor>() {
                    @Override
                    public WaterSensor map(String value) throws Exception {
                        String[] split = value.split(",");
                        return new WaterSensor(split[0], Long.parseLong(split[1]), Integer.parseInt(split[2]));
                    }
                });
        //3.获取表的执行环境
        StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);

        //流转表
        Table table = tableEnv.fromDataStream(waterSensrStream);

        //不注册直接使用
        //TableAPI
//        table
//                .groupBy($("id"))
//                .select($("id"),call(MyUDAF.class, $("vc")))
//                .execute()
//                .print();

        //先注册再使用 在sql中使用的话一定要先注册再使用
        tableEnv.createTemporarySystemFunction("avgVc", MyUDAF.class);
//        table
//                .groupBy($("id"))
//                .select($("id"),call("avgVc", $("vc")))
//                .execute()
//                .print();

        //SQL
        tableEnv.executeSql("select id,avgVc(vc) from "+table+" group by id").print();



    }

    public static class MyAvgAcc{
        public Integer vcSum;
        public Integer vcCount;
    }

    //聚合函数
   //求vc的平均值
  public static class MyUDAF extends AggregateFunction<Double,MyAvgAcc>{
        @Override
        public MyAvgAcc createAccumulator() {
            MyAvgAcc myAvgAcc = new MyAvgAcc();
            myAvgAcc.vcSum = 0;
            myAvgAcc.vcCount = 0;
            return myAvgAcc;
        }

        public void accumulate(MyAvgAcc acc,Integer value){
            acc.vcSum += value;
            acc.vcCount++;
        }

        @Override
        public Double getValue(MyAvgAcc accumulator) {
            return accumulator.vcSum*1D/accumulator.vcCount;
        }
    }

}
